git-annex/Remote/External.hs
Joey Hess f0195b2a43 Fix GETURLS in external special remote protocol to strip downloader prefix from logged url info before checking for the specified prefix.
This doesn't change what GETURLS returns, but only whether it matches
any prefix that the external special remote asked for.
2015-03-27 18:49:03 -04:00

453 lines
15 KiB
Haskell

{- External special remote interface.
-
- Copyright 2013 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Remote.External (remote) where
import Remote.External.Types
import qualified Annex
import Common.Annex
import Types.Remote
import Types.CleanupActions
import Types.UrlContents
import qualified Git
import Config
import Remote.Helper.Special
import Utility.Metered
import Logs.Transfer
import Logs.PreferredContent.Raw
import Logs.RemoteState
import Logs.Web
import Config.Cost
import Annex.UUID
import Creds
import Control.Concurrent.STM
import System.Log.Logger (debugM)
import qualified Data.Map as M
remote :: RemoteType
remote = RemoteType {
typename = "external",
enumerate = findSpecialRemotes "externaltype",
generate = gen,
setup = externalSetup
}
gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> Annex (Maybe Remote)
gen r u c gc = do
external <- newExternal externaltype u c
Annex.addCleanup (RemoteCleanup u) $ stopExternal external
cst <- getCost external r gc
avail <- getAvailability external r gc
return $ Just $ specialRemote c
(simplyPrepare $ store external)
(simplyPrepare $ retrieve external)
(simplyPrepare $ remove external)
(simplyPrepare $ checkKey external)
Remote
{ uuid = u
, cost = cst
, name = Git.repoDescribe r
, storeKey = storeKeyDummy
, retrieveKeyFile = retreiveKeyFileDummy
, retrieveKeyFileCheap = \_ _ -> return False
, removeKey = removeKeyDummy
, checkPresent = checkPresentDummy
, checkPresentCheap = False
, whereisKey = Nothing
, remoteFsck = Nothing
, repairRepo = Nothing
, config = c
, localpath = Nothing
, repo = r
, gitconfig = gc
, readonly = False
, availability = avail
, remotetype = remote
, mkUnavailable = gen r u c $
gc { remoteAnnexExternalType = Just "!dne!" }
, getInfo = return [("externaltype", externaltype)]
, claimUrl = Just (claimurl external)
, checkUrl = Just (checkurl external)
}
where
externaltype = fromMaybe (error "missing externaltype") (remoteAnnexExternalType gc)
externalSetup :: Maybe UUID -> Maybe CredPair -> RemoteConfig -> Annex (RemoteConfig, UUID)
externalSetup mu _ c = do
u <- maybe (liftIO genUUID) return mu
let externaltype = fromMaybe (error "Specify externaltype=") $
M.lookup "externaltype" c
(c', _encsetup) <- encryptionSetup c
external <- newExternal externaltype u c'
handleRequest external INITREMOTE Nothing $ \resp -> case resp of
INITREMOTE_SUCCESS -> Just noop
INITREMOTE_FAILURE errmsg -> Just $ error errmsg
_ -> Nothing
c'' <- liftIO $ atomically $ readTMVar $ externalConfig external
gitConfigSpecialRemote u c'' "externaltype" externaltype
return (c'', u)
store :: External -> Storer
store external = fileStorer $ \k f p ->
handleRequest external (TRANSFER Upload k f) (Just p) $ \resp ->
case resp of
TRANSFER_SUCCESS Upload k' | k == k' ->
Just $ return True
TRANSFER_FAILURE Upload k' errmsg | k == k' ->
Just $ do
warning errmsg
return False
_ -> Nothing
retrieve :: External -> Retriever
retrieve external = fileRetriever $ \d k p ->
handleRequest external (TRANSFER Download k d) (Just p) $ \resp ->
case resp of
TRANSFER_SUCCESS Download k'
| k == k' -> Just $ return ()
TRANSFER_FAILURE Download k' errmsg
| k == k' -> Just $ do
error errmsg
_ -> Nothing
remove :: External -> Remover
remove external k = safely $
handleRequest external (REMOVE k) Nothing $ \resp ->
case resp of
REMOVE_SUCCESS k'
| k == k' -> Just $ return True
REMOVE_FAILURE k' errmsg
| k == k' -> Just $ do
warning errmsg
return False
_ -> Nothing
checkKey :: External -> CheckPresent
checkKey external k = either error id <$> go
where
go = handleRequest external (CHECKPRESENT k) Nothing $ \resp ->
case resp of
CHECKPRESENT_SUCCESS k'
| k' == k -> Just $ return $ Right True
CHECKPRESENT_FAILURE k'
| k' == k -> Just $ return $ Right False
CHECKPRESENT_UNKNOWN k' errmsg
| k' == k -> Just $ return $ Left errmsg
_ -> Nothing
safely :: Annex Bool -> Annex Bool
safely a = go =<< tryNonAsync a
where
go (Right r) = return r
go (Left e) = do
warning $ show e
return False
{- Sends a Request to the external remote, and waits for it to generate
- a Response. That is fed into the responsehandler, which should return
- the action to run for it (or Nothing if there's a protocol error).
-
- While the external remote is processing the Request, it may send
- any number of RemoteRequests, that are handled here.
-
- Only one request can be made at a time, so locking is used.
-
- May throw exceptions, for example on protocol errors, or
- when the repository cannot be used.
-}
handleRequest :: External -> Request -> Maybe MeterUpdate -> (Response -> Maybe (Annex a)) -> Annex a
handleRequest external req mp responsehandler =
withExternalLock external $ \lck ->
handleRequest' lck external req mp responsehandler
handleRequest' :: ExternalLock -> External -> Request -> Maybe MeterUpdate -> (Response -> Maybe (Annex a)) -> Annex a
handleRequest' lck external req mp responsehandler
| needsPREPARE req = do
checkPrepared lck external
go
| otherwise = go
where
go = do
sendMessage lck external req
loop
loop = receiveMessage lck external responsehandler
(\rreq -> Just $ handleRemoteRequest rreq >> loop)
(\msg -> Just $ handleAsyncMessage msg >> loop)
handleRemoteRequest (PROGRESS bytesprocessed) =
maybe noop (\a -> liftIO $ a bytesprocessed) mp
handleRemoteRequest (DIRHASH k) =
send $ VALUE $ hashDirMixed def k
handleRemoteRequest (SETCONFIG setting value) =
liftIO $ atomically $ do
let v = externalConfig external
m <- takeTMVar v
putTMVar v $ M.insert setting value m
handleRemoteRequest (GETCONFIG setting) = do
value <- fromMaybe "" . M.lookup setting
<$> liftIO (atomically $ readTMVar $ externalConfig external)
send $ VALUE value
handleRemoteRequest (SETCREDS setting login password) = do
c <- liftIO $ atomically $ readTMVar $ externalConfig external
c' <- setRemoteCredPair encryptionAlreadySetup c (credstorage setting) $
Just (login, password)
void $ liftIO $ atomically $ swapTMVar (externalConfig external) c'
handleRemoteRequest (GETCREDS setting) = do
c <- liftIO $ atomically $ readTMVar $ externalConfig external
creds <- fromMaybe ("", "") <$>
getRemoteCredPair c (credstorage setting)
send $ CREDS (fst creds) (snd creds)
handleRemoteRequest GETUUID = send $
VALUE $ fromUUID $ externalUUID external
handleRemoteRequest GETGITDIR = send . VALUE =<< fromRepo Git.localGitDir
handleRemoteRequest (SETWANTED expr) =
preferredContentSet (externalUUID external) expr
handleRemoteRequest GETWANTED = do
expr <- fromMaybe "" . M.lookup (externalUUID external)
<$> preferredContentMapRaw
send $ VALUE expr
handleRemoteRequest (SETSTATE key state) =
setRemoteState (externalUUID external) key state
handleRemoteRequest (GETSTATE key) = do
state <- fromMaybe ""
<$> getRemoteState (externalUUID external) key
send $ VALUE state
handleRemoteRequest (SETURLPRESENT key url) =
setUrlPresent (externalUUID external) key url
handleRemoteRequest (SETURLMISSING key url) =
setUrlMissing (externalUUID external) key url
handleRemoteRequest (SETURIPRESENT key uri) =
withurl (SETURLPRESENT key) uri
handleRemoteRequest (SETURIMISSING key uri) =
withurl (SETURLMISSING key) uri
handleRemoteRequest (GETURLS key prefix) = do
mapM_ (send . VALUE) =<< getUrlsWithPrefix key prefix
send (VALUE "") -- end of list
handleRemoteRequest (DEBUG msg) = liftIO $ debugM "external" msg
handleRemoteRequest (VERSION _) =
sendMessage lck external $ ERROR "too late to send VERSION"
handleAsyncMessage (ERROR err) = error $ "external special remote error: " ++ err
send = sendMessage lck external
credstorage setting = CredPairStorage
{ credPairFile = base
, credPairEnvironment = (base ++ "login", base ++ "password")
, credPairRemoteKey = Just setting
}
where
base = replace "/" "_" $ fromUUID (externalUUID external) ++ "-" ++ setting
withurl mk uri = handleRemoteRequest $ mk $
setDownloader (show uri) OtherDownloader
sendMessage :: Sendable m => ExternalLock -> External -> m -> Annex ()
sendMessage lck external m =
fromExternal lck external externalSend $ \h ->
liftIO $ do
protocolDebug external True line
hPutStrLn h line
hFlush h
where
line = unwords $ formatMessage m
{- Waits for a message from the external remote, and passes it to the
- apppropriate handler.
-
- If the handler returns Nothing, this is a protocol error.-}
receiveMessage
:: ExternalLock
-> External
-> (Response -> Maybe (Annex a))
-> (RemoteRequest -> Maybe (Annex a))
-> (AsyncMessage -> Maybe (Annex a))
-> Annex a
receiveMessage lck external handleresponse handlerequest handleasync =
go =<< fromExternal lck external externalReceive
(liftIO . catchMaybeIO . hGetLine)
where
go Nothing = protocolError False ""
go (Just s) = do
liftIO $ protocolDebug external False s
case parseMessage s :: Maybe Response of
Just resp -> maybe (protocolError True s) id (handleresponse resp)
Nothing -> case parseMessage s :: Maybe RemoteRequest of
Just req -> maybe (protocolError True s) id (handlerequest req)
Nothing -> case parseMessage s :: Maybe AsyncMessage of
Just msg -> maybe (protocolError True s) id (handleasync msg)
Nothing -> protocolError False s
protocolError parsed s = error $ "external special remote protocol error, unexpectedly received \"" ++ s ++ "\" " ++
if parsed then "(command not allowed at this time)" else "(unable to parse command)"
protocolDebug :: External -> Bool -> String -> IO ()
protocolDebug external sendto line = debugM "external" $ unwords
[ externalRemoteProgram (externalType external)
, if sendto then "<--" else "-->"
, line
]
{- Starts up the external remote if it's not yet running,
- and passes a value extracted from its state to an action.
-}
fromExternal :: ExternalLock -> External -> (ExternalState -> v) -> (v -> Annex a) -> Annex a
fromExternal lck external extractor a =
go =<< liftIO (atomically (tryReadTMVar v))
where
go (Just st) = run st
go Nothing = do
st <- startExternal $ externalType external
void $ liftIO $ atomically $ do
void $ tryReadTMVar v
putTMVar v st
{- Handle initial protocol startup; check the VERSION
- the remote sends. -}
receiveMessage lck external
(const Nothing)
(checkVersion lck external)
(const Nothing)
run st
run st = a $ extractor st
v = externalState external
{- Starts an external remote process running, but does not handle checking
- VERSION, etc. -}
startExternal :: ExternalType -> Annex ExternalState
startExternal externaltype = liftIO $ do
(Just hin, Just hout, _, pid) <- createProcess $ (proc cmd [])
{ std_in = CreatePipe
, std_out = CreatePipe
, std_err = Inherit
}
fileEncoding hin
fileEncoding hout
checkearlytermination =<< getProcessExitCode pid
return $ ExternalState
{ externalSend = hin
, externalReceive = hout
, externalPid = pid
, externalPrepared = Unprepared
}
where
cmd = externalRemoteProgram externaltype
checkearlytermination Nothing = noop
checkearlytermination (Just exitcode) = ifM (inPath cmd)
( error $ unwords [ "failed to run", cmd, "(" ++ show exitcode ++ ")" ]
, do
path <- intercalate ":" <$> getSearchPath
error $ cmd ++ " is not installed in PATH (" ++ path ++ ")"
)
stopExternal :: External -> Annex ()
stopExternal external = liftIO $ stop =<< atomically (tryReadTMVar v)
where
stop Nothing = noop
stop (Just st) = do
void $ atomically $ tryTakeTMVar v
hClose $ externalSend st
hClose $ externalReceive st
void $ waitForProcess $ externalPid st
v = externalState external
externalRemoteProgram :: ExternalType -> String
externalRemoteProgram externaltype = "git-annex-remote-" ++ externaltype
checkVersion :: ExternalLock -> External -> RemoteRequest -> Maybe (Annex ())
checkVersion lck external (VERSION v) = Just $
if v `elem` supportedProtocolVersions
then noop
else sendMessage lck external (ERROR "unsupported VERSION")
checkVersion _ _ _ = Nothing
{- If repo has not been prepared, sends PREPARE.
-
- If the repo fails to prepare, or failed before, throws an exception with
- the error message. -}
checkPrepared :: ExternalLock -> External -> Annex ()
checkPrepared lck external =
fromExternal lck external externalPrepared $ \prepared ->
case prepared of
Prepared -> noop
FailedPrepare errmsg -> error errmsg
Unprepared ->
handleRequest' lck external PREPARE Nothing $ \resp ->
case resp of
PREPARE_SUCCESS -> Just $
setprepared Prepared
PREPARE_FAILURE errmsg -> Just $ do
setprepared $ FailedPrepare errmsg
error errmsg
_ -> Nothing
where
setprepared status = liftIO . atomically $ do
let v = externalState external
st <- takeTMVar v
void $ putTMVar v $ st { externalPrepared = status }
{- Caches the cost in the git config to avoid needing to start up an
- external special remote every time time just to ask it what its
- cost is. -}
getCost :: External -> Git.Repo -> RemoteGitConfig -> Annex Cost
getCost external r gc = go =<< remoteCost' gc
where
go (Just c) = return c
go Nothing = do
c <- handleRequest external GETCOST Nothing $ \req -> case req of
COST c -> Just $ return c
UNSUPPORTED_REQUEST -> Just $ return expensiveRemoteCost
_ -> Nothing
setRemoteCost r c
return c
{- Caches the availability in the git config to avoid needing to start up an
- external special remote every time time just to ask it what its
- availability is.
-
- Most remotes do not bother to implement a reply to this request;
- globally available is the default.
-}
getAvailability :: External -> Git.Repo -> RemoteGitConfig -> Annex Availability
getAvailability external r gc = maybe query return (remoteAnnexAvailability gc)
where
query = do
avail <- handleRequest external GETAVAILABILITY Nothing $ \req -> case req of
AVAILABILITY avail -> Just $ return avail
UNSUPPORTED_REQUEST -> Just $ return GloballyAvailable
_ -> Nothing
setRemoteAvailability r avail
return avail
claimurl :: External -> URLString -> Annex Bool
claimurl external url =
handleRequest external (CLAIMURL url) Nothing $ \req -> case req of
CLAIMURL_SUCCESS -> Just $ return True
CLAIMURL_FAILURE -> Just $ return False
UNSUPPORTED_REQUEST -> Just $ return False
_ -> Nothing
checkurl :: External -> URLString -> Annex UrlContents
checkurl external url =
handleRequest external (CHECKURL url) Nothing $ \req -> case req of
CHECKURL_CONTENTS sz f -> Just $ return $ UrlContents sz
(if null f then Nothing else Just $ mkSafeFilePath f)
-- Treat a single item multi response specially to
-- simplify the external remote implementation.
CHECKURL_MULTI ((_, sz, f):[]) ->
Just $ return $ UrlContents sz $ Just $ mkSafeFilePath f
CHECKURL_MULTI l -> Just $ return $ UrlMulti $ map mkmulti l
CHECKURL_FAILURE errmsg -> Just $ error errmsg
UNSUPPORTED_REQUEST -> error "CHECKURL not implemented by external special remote"
_ -> Nothing
where
mkmulti (u, s, f) = (u, s, mkSafeFilePath f)